Temporal variation and controlling factors of canopy conductance in Artemisia ordosica community
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摘要: 冠层导度(gc)是影响植物蒸腾和光合作用的重要参数，对环境变化敏感。本研究利用涡度相关法于2015年5—10月对毛乌素沙地油蒿群落的潜热和显热通量进行连续观测，并同步观测空气温度(Ta)、相对湿度(RH)、光合有效辐射(PAR)、土壤含水量(VWC)、降雨(PP)等气象因子，结合Penman-Monteith的冠层导度逆转方程，了解gc时间动态与变异机制。结果表明：研究区油蒿群落gc日变化具有明显的季节差异，夏季(5—8月)gc达到峰值的时间比秋季(9—10月)早约2 h，约在10:00左右达到峰值，比水汽压亏缺(VPD)和PAR的峰值分别提前3~4 h和1~2 h，秋季gc在中午12:00达到峰值后直接下降。PAR、VPD均对gc有显著的调控作用，PAR和VPD对gc的调控阈值分别是1 200 μmol/(m2·s)和1.5 kPa，小于阈值呈正相关，大于阈值呈负相关。30 cm土壤含水量(VWC_30)是调控gc的重要因子，当VWC_30大于0.16 m3/m3时，gc与VWC_30呈正线性关系。在高的土壤含水量条件(VWC_30≥0.16 m3/m3)下，gc对PAR和VPD的敏感性高于低土壤含水量(VWC_30 < 0.16 m3/m3)条件。结果表明，土壤水分是调节荒漠生态系统冠层导度的关键因子，研究结果为荒漠生态系统水文过程模型的建立提供重要参考。Abstract: Canopy conductance (gc) is an important factor influencing plant transpiration and photosynthesis, and it is sensitive to environmental factors. Evapotranspiration and environmental factors of a shrub ecosystem, which was dominated by Artemisia ordosica in northwestern China, were continuously measured using eddy covariance technique in growing season (May-October) in 2015. Meteorological variables including air temperature (Ta), relative humidity (RH), photosynthetic active radiation (PAR), soil volumetric water content (VWC), and precipitation (PP) were also measured. gc was calculated using the inverted Penman-Monteith equation. Diurnal pattern in gc revealed a clear seasonal trend, with gc peaking 2 hours earlier in summer (from May to August) than autumn(from September to October)(10:00, 3-4 hours and 1-2 hours before VPD and PAR). During growing season, gc increased positively with vapor pressure deficit (VPD) and PAR, respectively, saturating at 1.5 kPa and 1 200 μmol/(m2·s), then decreasing with these variables when greater than their respective threshold.The gc values had positive relationship with soil volumetric water content at 30 cm depth (VWC_30) under high VWC_30 (≥0.16 m3/m3) during the whole growing season. gc was more responsive to PAR and VPD when VWC_30 was high. It was concluded that VWC played a critical role in regulating canopy conductance in desert ecosystems. Our results could potentially provide important baseline information towards hydrological model creation of arid and semi-arid ecosystems.
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Keywords:
- canopy conductance /
- soil water content /
- semiarid region /
- transpiration /
- photosynthesis
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图 1 冠层导度、光合有效辐射和水汽压亏缺的日变化
Figure 1. Diurnal variation in canopy conductance (gc), photosynthetic active radiation (PAR) and vapor pressure deficit (VPD)
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图 2 冠层导度和环境因子的季节变化
VWC_10表示10 cm土壤含水量；VWC_30表示30 cm土壤含水量。
Figure 2. Seasonal variations in gc and environmental factors
VWC_10, VWC at 10 cm depth; VWC_30, VWC at 30 cm depth.
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图 4 冠层导度与光合有效辐射和水汽压亏缺的相关关系
Figure 4. Correlations between environmental factors PAR, VPD and gc
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图 5 不同水汽压亏缺条件下冠层导度对光合有效辐射的响应和不同PAR条件下gc对VPD的响应
Figure 5. Response of gc to PAR under different VPD and response of gc to VPD under different PAR
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图 6 30 cm土壤含水量对冠层导度和对gc与环境因子响应方式的影响
a.冠层导度(gc)对30 cm土壤含水量的响应；b.不同水分条件下gc对光合有效辐射(PAR)的响应；c.不同水分条件下gc对水汽压亏缺(VPD)的响应。
Figure 6. Effects of VWC at 30 cm depth (VWC_30) on gc and the way of gc responded to environment factors
a, response of canopy conductance (gc) to soil volumetric water content at 30 cm depth (VWC_30); b, response of gc to photosynthetic active radiation (PAR) under high and low VWC; c, response of gc to vapor pressure deficit (VPD) under high and low VWC.
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图 7 6—8月不同时刻(06：00—18：00)冠层导度(gc)与环境因子的敏感性
Figure 7. Sensitivity of canopy conductance (gc) to environment factors for each hour from 06:00-18:00 from June to August
表 1 不同30 cm土壤含水量冠层导度(gc)对光合有效辐射(PAR)和水汽压亏缺(VPD)的回归分析
Table 1 Regressions between canopy conductance (gc) and photosynthetic active radiation (PAR) and regressions between gc and vapor pressure deficit (VPD) under high and low soil volumetric water content at 30 cm depth (VWC_30)
PAR＜1 200 μmol/(m2·s) PAR≥1 200 μmol/(m2·s) VPD＜1.5 kPa VPD≥1.5 kPa VWC_30＜0.16m3/m3 VWC_30≥0.16m3/m3 VWC_30＜0.16m3/m3 VWC_30≥0.16m3/m3 VWC_30＜0.16m3/m3 VWC_30≥0.16m3/m3 VWC_30＜0.16m3/m3 VWC_30≥0.16m3/m2 a 0.001 3 0.001 7 -0.000 6 -0.001 8 0.56 0.81 0.67 0.95 b 0.43 0.46 2.43 4.66 0.57 0.73 1.95 2.31 R2 0.92 0.89 0.49 0.94 0.82 0.90 0.75 0.68 注：gc与PAR的拟合方程为：gc=a·PAR+b，a和b为线性回归分析得出的系数，R2为相关系数。当VPD＜1.5 kPa，gc与VPD的拟合方程为：gc=a·VPD+b，a和b为线性回归分析得出的系数。当VPD≥1.5 kPa，gc与VPD的拟合方程为：gc=-alnVPD+b，a和b为非线性回归分析得出的系数。Notes：the a and b in fitting equation of gc and PAR are coefficients obtained by linear regression analysis as the following equation form：gc=a·PAR+b, the letter R2 stands for the correlation coefficient. When VPD＜1.5 kPa, the a and b in fitting equation of gc and VPD are coefficients obtained by linear regression analysis as the following equation form：gc=a·VPD+b, the letter R2 stands for the correlation coefficient. When VPD≥1.5 kPa, the a and b in fitting equation of gc and VPD are coefficients obtained by non-linear regression analysis as the following equation form：gc=-alnVPD+b, the letter R2 stands for the correlation coefficient. 
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[1] BERRY J A, BEERLING D J, FRANKS P J. Stomata: key players in the earth system, past and present[J]. Current Opinion in Plant Biology, 2010, 13(3): 232-239. doi: 10.1016/j.pbi.2010.04.013
[2] PATALI D E, OREN R. Species differences in stomatal control of water loss at the canopy scale in a mature bottomland deciduous forest[J]. Advances in Water Resources, 2003, 26(12): 1267-1278. doi: 10.1016/j.advwatres.2003.08.001
[3] CHANG X, ZHAP W, LIU H, et al. Qinghai spruce (Picea crassifolia) forest transpiration and canopy conductance in the upper Heihe River Basin of arid northwestern China[J]. Agricultural and Forest Meteorology, 2014, 198-199: 209-220. doi: 10.1016/j.agrformet.2014.08.015
[4] BAI Y, ZHU G, SU Y, et al. Hysteresis loops between canopy conductance of grapevines and meteorological variables in an oasis ecosystem[J]. Agricultural and Forest Meteorology, 2015, 214-215: 319-327. doi: 10.1016/j.agrformet.2015.08.267
[5] IGARASHI Y, KUMAGAI T, YOSHIFUJI N, et al. Environmental control of canopy stomatal conductance in a tropical deciduous forest in northern Thailand[J]. Agricultural and Forest Meteorology, 2015, 202(15): 1-10. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=8fc545f18730dcc6a4603d23817f77d5
[6] 朱绪超, 袁国富, 邵明安, 等.塔里木河下游河岸柽柳林冠层导度变化特征及模拟[J].生态学报, 2016, 36(17): 5459-5466. http://d.old.wanfangdata.com.cn/Periodical/stxb201617019 ZHU X C, YUAN G F, SHAO M A, et al. Variation and predictive simulation of canopy conductance of a Tamarix spp. stand in the lower Tarim River Basin[J]. Acta Ecologica Sinica, 2016, 36(17): 5459-5466. http://d.old.wanfangdata.com.cn/Periodical/stxb201617019
[7] 李峥, 牛丽华, 袁凤辉, 等.辽西农林复合系统中杨树冠层导度特征[J].应用生态学报, 2012, 23(11): 2975-2982. http://d.old.wanfangdata.com.cn/Periodical/yystxb201211007 LI Z, NIU L H, YUAN F H, et al. Canopy conductance characteristics of poplar in agroforestry system in west Liaoning Province of Northeast China[J]. Chinese Journal of Applied Ecology, 2012, 23(11): 2975-2982. http://d.old.wanfangdata.com.cn/Periodical/yystxb201211007
[8] HERBST M, ROSIER P T, MORECROFT M D, et al. Comparative measurements of transpiration and canopy conductance in two mixed deciduous woodlands differing in structure and species composition[J]. Tree Physiology, 2008, 28(6): 959-970. doi: 10.1093/treephys/28.6.959
[9] KUMAGAI T, TATEISHI M, SHIMIZU T, et al. Transpiration and canopy conductance at two slope positions in a Japanese cedar forest watershed[J]. Agricultural and Forest Meteorology, 2008, 148(10): 1444-1455. doi: 10.1016/j.agrformet.2008.04.010
[10] AHLSTRÖM A, RAUPACH M R, SCHURGERS G, et al. The dominant role of semi-arid ecosystems in the trend and variability of the land CO2 sink[J]. Science, 2015, 348: 895-899. doi: 10.1126/science.aaa1668
[11] WANG B, ZHA T S, JIA X, et al. Soil moisture modifies the response of soil respiration to temperature in a desert shrub ecosystem[J]. Biogeosciences Discussions, 2013, 10(6): 9213-9242. doi: 10.5194/bgd-10-9213-2013
[12] QIAN D, ZHA T, JIA X, et al. Adaptive water-conserving strategies in Hedysarum mongolicum endemic to a desert shrubland ecosystem[J]. Environmental Earth Sciences, 2015, 74(7): 6039-6046. doi: 10.1007/s12665-015-4627-9
[13] 李思静, 查天山, 秦树高, 等.油蒿(Artemisia ordosica)茎流动态及其环境控制因子[J].生态学杂志, 2014, 33(1): 112-118. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=stxzz201401017 LI S J, ZHA T S, QIN S G, et al. Temporal patterns and environmental controls of sap flow in Artemisia ordosica[J]. Chinese Journal of Ecology, 2014, 33(1): 112-118. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=stxzz201401017
[14] XIE J, ZHA T, JIA X, et al. Irregular precipitation events in control of seasonal variations in CO2 exchange in a cold desert-shrub ecosystem in northwest China[J]. Journal of Arid Environments, 2015, 120: 33-41. doi: 10.1016/j.jaridenv.2015.04.009
[15] JIA X, ZHA T S, WU B, et al. Biophysical controls on net ecosystem CO2 exchange over a semiarid shrubland in northwest China[J]. Biogeosciences Discussions, 2014, 11(3): 4679-4693. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=Doaj000003573274
[16] 钱多.毛乌素沙地混交灌木林蒸腾耗水与水量平衡特征[D].北京: 北京林业大学, 2016. http://cdmd.cnki.com.cn/Article/CDMD-10022-1016145142.htm QIAN D. Transpiration characteristics and water balance of a mixed shrubland in Mu Us Desert[D]. Beijing: Beijing forestry university, 2016. http://cdmd.cnki.com.cn/Article/CDMD-10022-1016145142.htm
[17] 王辉, 贺康宁, 徐特, 等.柴达木地区沙棘冠层导度特征及模拟[J].北京林业大学学报, 2015, 37(8): 1-7. doi: 10.13332/j.1000-1522.20140457 WANG H, HE K N, XU T, et al. Characteristics and simulation of the canopy conductance of Hippophae rhamnoides in Qaidam Region of northwestern China[J]. Journal of Beijing Forestry University, 2015, 37(8): 1-7. doi: 10.13332/j.1000-1522.20140457
[18] COWAN I R. Stomatal behaviour and environment[J]. Advances in Botanical Research, 1978, 4: 117-228. doi: 10.1016/S0065-2296(08)60370-5
[19] 黄辉, 于贵瑞, 孙晓敏, 等.华北平原冬小麦冠层导度的环境响应及模拟[J].生态学报, 2007, 27(12): 5209-5221. doi: 10.3321/j.issn:1000-0933.2007.12.031 HUANG H, YU G R, SUN X M, et al. The environmental responses and simulation of canopy conductance in a winter wheat field of North China Plain[J]. Acta Ecologica Sinica, 2007, 27(12): 5209-5221. doi: 10.3321/j.issn:1000-0933.2007.12.031
[20] 李媛, 查天山, 贾昕, 等.半干旱区典型沙生植物油蒿(Artemisia ordosica)的光合特性[J].生态学杂志, 2015, 34(1): 86-93. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=stxzz201501012 LI Y, ZHA T S, JIA X, et al. Photosynthetic characteristics of typical desert plant Artemisia ordosica in semi-arid region[J]. Chinese Journal of Ecology, 2015, 34(1): 86-93. http://www.wanfangdata.com.cn/details/detail.do?_type=perio&id=stxzz201501012
[21] 赵平.整树水力导度协同冠层气孔导度调节森林蒸腾[J].生态学报, 2011, 31(4): 1164-1173. http://d.old.wanfangdata.com.cn/Periodical/stxb201104030 ZHAO P. On the coordinated regulation of forest transpiration by hydraulic conductance and canopy stomatal conductance[J]. Acta Ecologica Sinica, 2011, 31(4): 1164-1173. http://d.old.wanfangdata.com.cn/Periodical/stxb201104030
[22] NAITHANI K J, EWEIS B E, PENDALL E. Sap flux-scaled transpiration and stomatal conductance response to soil and atmospheric drought in a semi-arid sagebrush ecosystem[J]. Journal of Hydrology, 2012, 464-465: 176-185. doi: 10.1016/j.jhydrol.2012.07.008
[23] ZHA T S, LI C, KELLOMÄKeI S, et al. Controls of evapotranspiration and CO2 fluxes from scots pine by surface conductance and abiotic factors[J/OL]. PloS One, 2013, 8(7): e69027[2016-08-14]. DOI: 10.1371/journal.pone.0069027.
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